W00t! Finally got some gas going (and no I don't mean Dad's cooking)! :)
Arr, she blows! Hot air that is, and that's a good thing too.
Looking down the tube. Construction is the basic Reil design, using a 3/4" dia. 8" long pipe for the burner tube, a 1" to 3/4" reducer for the venturi, and a 1/4" copper tube with a #57 hole cross-drilled in one side. The tube is presurized by the propane regulator and gas shoots out the hole, down the tube. More information can be found on Ron Reil's site.
(Click to enlarge.) Staring it down, adjusting the regulator to see what it'll do. So far it works fully from a few PSI to the 35PSI maximum the regulator is rated for. (I don't have a pressure guage to measure it.) At low pressure, less than maybe 5PSI, it starts oscillating, and real low it pulsates. I can't really describe it, but I can tell you that when it's popping like this at high throttle it sounds like what a pulsejet must sound like. Of course, it doesn't put out much thrust. ;) (Speaking of pulsejets, a kickass site is Bruce Simpson's.)
Looks pretty warm, doesn't it? It's actually all camera effects. The only glow is coming from the refractory right by the burner, and it's just lighting up the rest of it. The orange flames are from the flame hitting the refractory. I need to take a sledge to this thing and rebuild it with commercial refractory ... but I don't have $175. :(
Didn't melt any metal this day, just testing the burner in-situ. So far it's been well-behaved; I've also brazed a strap onto the gas tube, since the two screws holding it in were always coming loose. (The cast iron reducer is unusually high quality iron and is practically as slippery as teflon, as metals go.) With the strap (which is attached to the venturi with an 8-32 screw), even if the screws come loose, the tube will not slide out.